The effect of clonidine premedication on hemodynamic responses to microlaryngoscopy and rigid bronchoscopy.

The usual hemodynamic response to laryngoscopy and bronchoscopy is an increase in heart rate and arterial blood pressure. Previous work has reported that 10%-18% of the patients develop ischemic ST segment changes during the procedure. Therefore, we performed a prospective, randomized, double-blinded study in 36 patients scheduled for elective microlaryngeal and bronchoscopic surgical procedures to evaluate the effects of 300-microg oral clonidine premedication (n = 18) or placebo (n = 18) on the hemodynamic alterations and the incidence of perioperative myocardial ischemic episodes. Myocardial ischemia was assessed by using continuous electrocardiographic monitoring, beginning 30 min before, and lasting until 24 h after the operation. During the procedure, patients receiving placebo exhibited a significant increase (mean +/- SD) in arterial blood pressure (the systolic increasing from 137+/-11 to 166+/-17 mm Hg, the diastolic increasing from 80+/-11 to 97+/-14 mm Hg) and heart rate (increasing from 79+/-15 to 97+/-12 bpm) compared with the baseline and with the clonidine group. A dose of 300-microg clonidine blunted the hemodynamic response to endoscopy. Ventricular arrhythmias were more frequent in patients who were not premedicated with clonidine. Two patients in the control group, but none in the clonidine group, had evidence of myocardial ischemia. These data should encourage routine premedication with clonidine in patients undergoing microlaryngoscopic and bronchoscopic procedures.

[Can police car flashing lights induce a risk of encephalographic epileptic discharges and seizures?].

The new police car flashing-light device (930 Heliobe Lightbar) has recently been implicated as potentially epileptogenic. We exposed 30 epileptic patients, 30 nonepileptic patients who suffered from headache and 15 normal volunteers to this light source. All had routine EEGs with standard intermittent photic stimulation, followed by 3-minute stimulation with the Lightbar. In none were either seizures or EEG changes induced. In 1 epileptic spike-and-wave activity induced by standard photic stimulation was enhanced with the Lightbar. We could not confirm that the Lightbar is epileptogenic.